At present, a display component of an LCD widely applied to a mobile terminal is laminated to a Capacitive Touch Panel (CTP) to be assembled with a front shell of the mobile terminal for use as a whole. Character keys below a touch panel are required to be lightened according to a specific operation mode. In order to uniquely lighten character keys, it is necessary to independently sandwich a light guide plate between the LCD and the CTP and guide light into a character area, which may cause influence on an LCD and CTP lamination process, reduce a lamination yield and moreover, produce bright lines in an area close to the characters on the whole screen under some circumstances.